The present invention relates generally to a system and method for treating conditions of the brain. More specifically, the present invention relates to a catheter assembly and method for intraventricular shunting and lavage for the change of neurophysiological imbalances in the central nervous system (CNS).
Apoprotein and other substances accumulate in the brain tissues of patients suffering from cognitive impairment associated with aging (e.g., Alzheimer's disease). Patients in a coma after traumatic head injury, patients suffering from dementia, and patients with a variety of other psychiatric disorders are also known to display imbalances or deficiencies of a variety of cerebral neurotransmitters and electrolytes.
Patients in a coma after traumatic head injury are known to display several kinds of neurophysiological disequilibria, for example, excessively high intracranial pressure which may depress the regulation of vital functions or create deficits of neurotransmitters such as Acetylcholine or serotonin resulting in a diminution of activating and arousal processes.
Precursors and metabolites of neurotransmitters are also present in the cerebrospinal fluid (CSF) which establishes an equilibrium by diffusion with the extracellular fluid (ECF) which is the intimate environment of the parenchyma tissue, neurons and glia. The CSF concentrations of these substances may provide clinically useful information about excesses or deficits of neurotransmitters in the tissue.
Such neurophysiological disequilibria may result in a build up of toxic substances in the CSF. Excessive amounts of metabolite produced in one brain region may diffuse via the CSF to other regions where they may alter the balance of reversible reactions. Intracranial pressure (ICP) may increase, causing depression of centers in the brainstem that are essential for maintenance and regulation of vital functions. Such alterations of normal ICP are encountered in clinical conditions such as hydrocephalus or traumatic brain injury. The CSF may be drained from the CSF space to adjust the ICP, and the concentrations of metabolites or precursors of critical substances may be subjected to microassay outside the cranium.
The removal of CSF to treat Alzheimer's disease, hydrocephalus, brain edema, or other diseases may be accomplished by the use of a variety of intracranial devices, as is known in the art. To remove these undesirable toxic substances or correct these undesirable pressures, a drainage device such as a shunt or a catheter may be placed in a ventricle of the brain.